1. Field of the Invention
The present invention relates to a vascular prosthesis, methods of manufacturing such a prosthesis and to a substrate suitable for manufacturing the prosthesis. More particularly, the invention relates to a vascular prosthesis having tissue fragments and/or cells adhered to and captured within the wall of the prosthesis, to methods of manufacturing such a vascular prosthesis and to substrates suitable for manufacturing such vascular prostheses.
2. Description of Prior Art
Various vascular prostheses are known. Some are made of synthetic polymers such as polytetrafluoroethylene or polyester. Others are made of human cord veins, animal blood vessels and of various biological tissues crosslinked with glutaraldehyde as the crosslinking agent. When such vascular prostheses are placed in a mammalian or human body, the inner walls of the prostheses become coated with endothelial cells, which possess antithrombotic properties for preventing blood clotting and deposition of thrombus on the inner walls.
In actual clinical applications, however, coating by the endothelial cells is usually extremely delayed and, in most cases, only the area of the anastomosis of the vascular graft becomes covered with endothelial cells while positions remote from the anastomosis are not covered. Accordingly, thrombus deposits form the inner wall of the vascular prosthesis, blocking the vascular graft.
In order to prevent this problem, it is known to introduce endothelial cells onto the inner wall of the vascular graft in advance. For example, endothelial cells cultivated in vitro are deposited onto the inner wall of the prosthesis by various techniques. However, when a prosthesis so obtained is transplanted into the body of a mammal, the graft is dilated by blood pressure, causing cracks in the cell deposits. The cells can then separate and be washed away by the blood flow. As a result, this technique has not been clinically applied.